Ozone generators are loads with highly capacitive performance. In order to feed the ozone generator which works as a capacitive load, the electric power supply equipment which consists of large capacity components, such as a transformer, a reactor, an inverter and the like will be utilized. These components are fed with high voltages and generate a large quantity of heat, and hence, efficient cooling is required to these components. Inside of a panel board of the electric power supply equipment, a heat exchanger is provided and cooling the inside of the panel board is performed by way of the heat exchanger. The transformer, the reactor, and the inverter are expected to have a structure with high cooling efficiency.
In order to achieve the weight saving and cost reduction of the reactor which is to be used in the electric power supply equipment, the method of using an air core type reactor has been known. Air core type reactors have been devised, including one which has a winding wire of toroidal shape in order to hold down the leakage magnetic flux (for example, refer to Patent Documents 1 and 3); another which is manufactured with only a multi parallel line body, so that the magnetic fields of the coils, which lie next to each other, may become opposite in the direction (for example, refer to Patent Document 4); in addition, a third the periphery of which is covered with an electromagnetism shield (for example, refer to Patent Document 2); and the fourth which circulates magnetic fluxes using top to bottom bundle boards of steel plate or the like (for example, refer to Patent Document 5).